This trivially makes "git-shell" a built-in. It makes the executable even
fatter, though.
And MinGW removed git-shell only because of the funny dependencies; there
is no reason to do so anymore.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Tested-on-MinGW-by: Johannes Sixt <johannes.sixt@telecom.at>
